When cleaning the AC filters on our 2015 EB with dual AC, I found this loose cable coiled inside the zone 2 unit labeled "T STAT EXT" (see pic). I assume this means thermostat extension or similar, but what would it be be used for or connected to? Perhaps an exterior thermostat, for units with that option? Thanks in advance, Joe

to run the wire to an external thermostat making your roof AC act more like central air in a house, or maybe the thermostat controlled heat in your rig. Normally the thermostat is right there with the AC.

If the thermostat is right by the AC unit, some, like me, may prefer to have the sensor nearer to where we actually spend most time in the trailer. Additionally, if, like mine originally, the stat is an analogue device (e.g. a rotary knob with a printed range of temperatures), then it is not the most precise and useful controller.
A digital thermostat mounted on a wall in a more useful area solves these issues for me. The cable you describe may enable this modification with minimum wiring complexity.
I described full details of the fitting of my remote digital thermostat ,for the AC and the furnace combined, eleven years ago here:http://www.airforums.com/forums/f427...ace-14953.html
Nick.